Ground sleeve having improved impedance control and high frequency performance

Abstract

A waferized connector connects to two twinax cables. The connector includes a molded lead frame, ground sleeve, twinax cable, and overmolded strain relief. The lead frame is molded to retain a lead frame containing both differential signal pins and ground pins. Termination sections are provided at the rear of the lead frame to terminate each of the signal wires of the cables to respective signal lands. The ground sleeve has two general H-shape structures connected together by a center cross-support member. Each of the H-shaped structures having curved legs, each of which fits over the signal wires of one of the twinax cables. The wings of the ground sleeve are terminated to the ground lands of the lead frame and the drain wire of the cable is terminated to the ground sleeve to terminate the drain wire to a ground reference. The ground sleeve controls the impedance in the termination area of the cables, where the twinax foil is removed to expose the wires for termination to the lands. The ground sleeve also shields the cables to reduce crosstalk between themselves and adjacent wafers when arranged in a connector housing. A conductive slab member is formed over the sleeve to provide a capacitive coupling with the conductive foil of the signal cable.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a ground sleeve. More particularly, the present invention is for a reference ground sleeve that controls impedance at the termination area of wires in a twinax cable assembly and provides a signal return path.[0003]2. Background of the Related Art[0004]Electrical cables are used to transmit signals between electrical components and are often terminated to electrical connectors. One type of cable, which is referred to as a twinax cable, provides a balanced pair of signal wires within a conforming shield. A differential signal is transmitted between the two signal wires, and the uniform cross-section provides for a transmission line of controlled impedance. The twinax cable is shielded and “balanced” (i.e., “symmetric”) to permit the differential signal to pass through. The twinax cable can also have a drain wire, which forms a ground reference in conjunction with the twinax foil or braid....

AI Technical Summary

Benefits of technology

The invention is a connector that is designed to control the impedance in the termination region of a cable, specifically a twinax cable. The connector includes a plastic insert molded lead frame, ground sleeve, twinax cable, and integrated plastic over molded strain relief. The lead frame is designed to retain both differential signal pins and ground pins, while the ground sleeve has curved legs that fit over the signal wires of the cable. The ground sleeve also shields the cables to reduce crosstalk between multiple wafers when arranged in a connector housing. The technical effects of the invention include controlling the impedance in the termination region of a cable, matching the impedance in the termination region of differential signal wires, matching the impedance in the termination region of a twinax cable, and controlling the impedance in the termination region of a twinax cable as it is connected to leads of an electrical connector.

Problems solved by technology

However, in order to terminate the signal and ground wires of the cable to a connector or electrical element, the geometry of the transmission line must be disturbed in the termination region i.e., in the area where the cables terminate and connect to a connector or electrical element.

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